IT HAS BEEN A LONG TIME since an exhibition has provoked the kind of intense debates that greeted the Musée du Louvre’s “De l’Allemagne, 1800–1939: German Thought and Painting, from Friedrich to Beckmann.” All the ambition of the enterprise was contained in its title, which asserted the show’s place within a prestigious intellectual genealogy. In 1813, Madame de Staël published her book De l’Allemagne, a fervent defense of the German thought of her time. She saw in German idealism and Romanticism the very blooming of modernity, the advent of a liberal Christian Europe that would look to the Middle Ages, not the classical norm of the Enlightenment, for its inspiration. Twenty years later, in a book also titled De l’Allemagne, poet Heinrich Heine attacked these views with his customary mordant irony. For him, this pseudo-spiritual revolution was, in reality, a reactionary move, a